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How to use a camera lucida

The camera lucida is generally considered to have been invented by the English chemist W. H. Wollaston in 1806-07, although there is some speculation that it is a reinvention of a device described by Kepler some 200 years earlier. The term camera lucida means 'light room' and it indicates that the device didn't require the darkened space that had been necessary for the earlier camera obscura. There is no projected image and it is based on very different optical principles. A camera lucida consists of a simple prism and lens that allow an artist to see the scene that they depicting superimposed over the paper that they are drawing on, so that they can simply trace around the image. The rest of the device comprises of a clamp and extendable arm, with which it can be securely fixed in position to one side of the artist's drawing board or sketch pad with the prism set at a convenient height.

A French camera lucida or 'Chambre Claire Universelle', made by Breveté S.G.D.G., with a set of 12 numbered lenses.

Detail of the prism (set within the black holder) and lens.

Looking downwards through the very edge of the prism, the subject is seen the correct way up on the drawing surface, as shown in the above photos.

As the superimposed images tend to be quite faint, white paper can be too bright for the image to appear clearly. Drawing in chalk on black paper can be used to achieve better results.

These instructions for the 'Chambre Claire Universelle' explain which of the different numbered lenses is to be used in various circumstances, dependant on the height of the prism above the paper and the distance of the subject being drawn. Increasing the height of the prism above the drawing surface creates a larger image.

A 19th century engraving by C. Varley made using a camera lucida, depicting G. Dollond who is also drawing with the device. George Dollond (1774-1852), who was a noted maker of telescopes and other optical instruments, helped popularise the camera lucida in England.

It was after using a camera lucida in 1833 that the the pioneer of photography William Fox Talbot began his attempts to fix images chemically.

1 comment:

Excuse me if I am out of line here, but I thought that anyone reading it might be interested in a workshop on making images with pre-photographic equipment at the George Eastman House.Participants have the opportunity to make and use their own camera obscuras, a tent camera obscura and camera lucida to make drawings in the formal gardens, and will use a pantograph and a physionotrace to make silhouette portaits of one another. Read more here: http://www.eastmanhouse.org/events/detail/photo-workshop-12-2012

Glossary

accelerated perspective - the use of exaggerated perspective effects in architecture to give an enhanced sense of spatial depth.

aerial perspective - the impression of depth created by the reduction in contrast of objects in the distance, which is caused by atmospheric haze.

anamorphosis - an image that has been distorted, so that it can only be seen correctly when viewed from a specific point.

artificial perspective - a term for perspective drawings that are based on Albertian principles (in contrast to 'synthetic perspective').

centre line - the line leading from the viewpoint to the point on the picture plane that is directly in front of the viewer's eye.

cone of vision - the cone of visual rays that converge at the eye or 'viewing position'.

Construzione Legittima - the term used by Alberti to describe his method of perspective construction.

crate - a notional orthogonal box placed around a complex object to make it easier to draw.

curved picture plane - a cylindrical or spherical picture plane, used in an attempt to more accurately depict an image as it would appear to the eye, or to emulate a fish-eye camera lens.

cylinder anamorphosis - an image that has been distorted, so that it can only be seen correctly when viewed reflected in a cylindrical mirror.

diagonal perspective - a perspective view that looks diagonally towards the principal surfaces of an object.

diagonal vanishing point (DVP) - the point on the horizon towards which any diagonal lines in the object will converge.

distance point - another term for a diagonal vanishing point.

distortion - a term used to describe the 'unnatural' appearance of objects when drawn in perspective, particularly when wide angles of view are used.

eye point - the point on the picture plane that is directly in front of the viewer's eye. The eye point is always on the horizon.

horizon - the notional horizontal line in the far distance, dividing the earth from the sky.

horizon line - in a perspective drawing, this is a horizontal line at eye level. Vanishing points for all horizontal edges will be on the horizon line.

linear perspective - an alternative term for 'artificial perspective'.

natural perspective - an alternative term for 'synthetic perspective'.

non-parallel perspective - an alternative term for 'diagonal perspective'.

object centred - a drawing system based on representing an object without reference to a specific experiential viewpoint. Plans, sections, elevations and axonometrics are all form of object centred drawings.

one-point perspective - a common term for 'parallel perspective', (although the drawing may in fact include more than one vanishing points).

parallel perspective - a perspective view that is aligned in parallel with the principal surfaces of an object.

perspective 'window' - an alternative term for the 'picture plane'.

picture plane - the notional intersection of the visual cone on which the position of the visual rays are plotted.

retinal image - a notional description of how a view may appear on the retina of the eye.

sciagraphical perspective - the projection of shadows in perspective.

spectator point - see 'viewing position'.

synthetic perspective - drawings based on a curved picture plane.

two-point perspective - a common term for diagonal perspective (although the drawing may in fact include more than two vanishing points).

vanishing point (VP) - a point on the horizon towards which a set of parallel lines will converge.

vertical datum - an intersection of the object with the picture plane at which a vertical scale can easily be determined.

viewer centred - a drawing system, based on a spectator's viewpoint. A perspective drawing is one type of viewer centred system.

viewing distance - the distance between the spectator and the object depicted or picture plane.

viewing position - the fixed view point from which a perspective view is constructed.

viewpoint - see 'viewing position'.

visual pyramid - the cone of visual rays that converge at the eye or 'viewing position'.

visual rays - a straight line, running from a point on an object to the eye.